Graphene Field Effect Biosensor for Concurrent and Specific Detection of SARS-CoV-2 and Influenza

Abstract

The SARS-CoV-2 pandemic has highlighted the need for devices capable of carrying out rapid differential detection of viruses that may manifest similar physiological symptoms yet demand tailored treatment plans. Seasonal influenza may be exacerbated by COVID-19 infections, increasing the burden on healthcare systems. In this work, we demonstrate a technology, based on liquid-gated graphene field-effect transistors, for rapid and ultraprecise detection and differentiation of influenza and SARS-CoV-2 surface protein. The device consists of 4 onboard graphene field-effect electrolyte-gated transistors arranged in a quadruple architecture, where each quarter is functionalized with either antigen-specific antibody or chemically passivated control. The antigen-antibody interaction is dependent on uniform diffusion of virus delivered in low ionic strength phosphate buffer solution, entailing a facile operating procedure, where the user adds a drop of the viral surface protein solution onto the device. Our sensor platform was tested against a range of concentrations of viral surface proteins from both viruses with the lowest tested and detected concentration at ~50 ag/mL, or 88 zM for COVID-19 and 227 zM for Flu, 5-fold lower than the values reported previously on a similar platform. Unlike the contemporary standard, RT-PCR test, which have a turnaround time of a few hours, the reported graphene biosensor technology has a fast response time of ~10 seconds enabling rapid diagnosis. Furthermore, the antibodies tested were confirmed to be antigen-specific through cross-reactivity tests. Thus, we have developed a multi-virus, highly sensitive and specific detection tool for rapid diagnostic applications for contemporary, emerging, and future viruses.

Sensitivity-Enhancing Strategies of Graphene Field-Effect Transistor Biosensors for Biomarker Detection

“…60 Addressing metal ion contamination, Kumar et al replaced FeCl 3 with (NH 4 ) 2 S 2 O 8 , enhancing GFET biosensors for detecting novel coronavirus and influenza with 88 zM and 227 zM. 61 To mitigate PMMA residue effects, thermal treatment and Ar plasma treatment have been explored. Yu et al 49 demonstrated solvent and impurity removal by annealing in high-purity Ar (Figure 2a), while Yang Cheng's group 50 improved sensitivity (LoD of 10 aM) by using Ar plasma to volatilize PMMA, presenting nondestructive graphene cleaning albeit with greater complexity (Figure 2b).…”

“…Reproduced with permission. 61 Copyright 2023, ACS Nano. (e) Bilayer graphene is functionalized through a low-damage nitrogen plasma treatment, and then further modified with specific antibodies to enable a label-free detection of CTCs.…”

“…To date, various types of biomolecules, including peptides, antibodies, enzymes, aptamers, and DNA probes, have been successfully immobilized onto graphene via PBASE linkers, exhibiting excellent electrical properties. 61,96,97 Its highly flexible alkyl chain end may lead to various orientations of antibodies on the graphene surface, potentially impacting the completeness of immune reactions (Figure 3d). Yin et al 98 addressed the issue of multiorientation of antibodies by employing tetra (4-carboxyphenyl) porphyrin (TCPP) functionalization of graphene.…”

“…The strategy of employing covalent organic frameworks (COFs) on graphene surfaces not only encapsulates and shields the channels from contamination but also provides a high specific surface area amenable to receptor modifications. 152 To further reduce the nonspecific binding one can do internal referencing (e.g., having a nonbinding element on the same device 61 ). Hao et al 141 introduced an intelligent dual-channel GFET biosensor modified with TWEEN 80 for on-site and wireless detection of cytokines (including IFN, IL, and TNF) in human biological fluids such as serum, saliva, urine, and sweat.…”

Transistors platform for rapid and parallel detection of multiple pathogens by nanoscale-localized multiplexed biological activation

“…Furthermore, the detection limits of FET-based sensors have been pushed to ultralow concentrations (i.e., femto-molar or less) by adapting nanoscale materials such as nanowires [9,10], In 2 O 3 [7], and graphene [11][12][13]. The progress in this direction promises new applications for FET-based sensor technologies in drug discovery [14,15] and clinical diagnostics [16][17][18][19].…”